Such an implant is known from EP 0 950 388 [U.S. Pat. No. 6,190,413]. This implant is comprised of a total of three implant is parts; two end permanent parts installed on the adjacent vertebra, and one center implant part positioned between them, which are connected to each other via screwthreads. Holes are formed in the end implant parts serving primarily for enabling access to the interior of the implant parts for inserting bone cement or bone material. These holes are also utilized to optionally attach a mounting bracket having a circular collar to one of the end implant parts, holes being formed in the collar that can be aligned with two holes formed in the end implant part. Bolts can be fitted through the aligned holes. The mounting bracket has a longitudinal slot whose width varies such that the pins can be fixed in the holes. As a result the mounting bracket is attached at the outer edge of the end implant part, and can be utilized to improve the stability of the spine without preventing access to the implant parts.
One disadvantage of this known implant, however, is that it is subject to limitation in increasingly used minimal invasive surgery, because in order to change the length of the implant the center implant must be adjusted as opposed to the end implant part by attaching to it a tool that moves in a circular arc, and adjustment to the individual conditions of the patient is not possible due to the arrangement of the mounting bracket on the outer circumference of the end implant part.